Starting up large motors on single-phase lines has long been a challenge for electric co-ops. Single-phase motors create voltage sags and flickers for the customer and can cause problems for neighbors. Customers who need large motors typically face difficult choices. Spend as much at $100,000 per mile for three-phase power or, more likely, install three-phase motors with a phase converter connected to a single-phase line.
The Written-Pole® motor technology from Single Phase Power Solutions, Cincinnati, Ohio, provides a third alternative. Single Phase Power Solutions sells BELL Single-Phase Written-Pole® motors ranging from 30 hp to 100 hp. Designed to avoid power quality problems, a BELLE Written-Pole® motor typically requires a start-up current less that twice its running current, unlike conventional AC motors, which can draw from eight to ten times more current during start-up than during normal operation.
The motors operate at about 97% efficiency compared to 85% for conventional induction motors. BELLE Written-Pole® motors are the best choice for those who need a large horsepower solution but only have access to single-phase power.
Single Phase Power Solutions also offers a 1-to-3 Three-Phase Microgrid that uses a BELLE Written-Pole® single-phase motor to drive a three-phase generator that then creates three-phase power for the end user. The 1-to-3 system outputs 40kW to 50KVA. It can restart instantly after momentary power outages and eliminated flickers and voltage sags. Single Phase Power Solutions has motors and 1-to-3 Microgrids installed throughout North America.
Pat Trask, owner of the Spanish Five Ranch in Wasta, SD, installed a 60 hp BELLE Written-Pole in June 2004. Trask uses irrigation pumps and had be limited by his co-op to a 30 hp, three-phase motor with a phase converter.
In drought conditions, Trask has been forced to pump water for 2,300 consecutive hours to irrigate 250 acres of land. Peak electricity demand often causes frequent power interruptions with shutdowns and restarts of the pump. The outages caused premature failures of components and fuses of the phase converter. A propane engine was installed to power a larger pump. However, propane prices had doubled since the installation of the engine.
Looking for alternatives to the propane engine, Trask installed a BELLE Single-Phase Written-Pole® motor. Since the installation, the ranch has enjoyed virtually uninterrupted service because the motor overrides blinks.
“This motor has operated flawlessly since its installation,” says Trask. “We are pumping 35% more water with a 52% decrease in energy cost. This motor is a dream come true.”